This web site is for scientists and astronomy enthusiasts seeking information
on and actual data from a multitude of
space-based observatories. On this
site, you can find archival data, multi-mission and mission-specific software
and analysis tools, and information about current and past observatories and
missions. These materials are all available freely for your use.

The High Energy Astrophysics Science Archive Research Center (HEASARC) is
supported by the
Astrophysics Division of NASA's Science Mission Directorate. It
is the primary archive for high-energy astronomy orbital missions observing at
extreme ultraviolet, X-ray and gamma-ray wavelengths. Several of these
missions, including Chandra, Fermi and XMM-Newton, fall under NASA's
Physics of the Cosmos (PCOS)
theme, while others, such as NICER, NuSTAR and Swift, are part of NASA's
Explorers program.
Since its merger with the Legacy
Archive for Microwave Background Data Analysis (LAMBDA) in 2008,
the HEASARC's holdings also include data from space-based
missions, balloons, and ground-based facilities, such as COBE, WMAP, ACT,
etc., that have studied the relic cosmic microwave background (CMB).

The HEASARC is a service of the Astrophysics Science
Division at NASA/GSFC and of the High Energy Astrophysics Division of the Smithsonian Astrophysics
Observatory (SAO). The SAO HEASARC web site contains information about and links to FITS
file formats, atomic databases, and software developed in whole or in part at
SAO, e.g., AtomDB, DS9, XPA, etc. These projects may or may not have been
funded directly via HEASARC
grants, but are related to HEASARC objectives and thus included on the
SAO HEASARC web site.